1. Field of the Invention
The present invention relates to an apparatus and process for making shaped confectionery products from a fat based material, e.g., chocolate. More particularly, the present invention relates to an apparatus and process used in making shaped confectionery centers by a forming process, such as cold forming, where the shaped confectionery centers have an internal hollow section.
2. Description of the Related Art
Confectionery centers may be manufactured by various methods, including drop roll forming techniques where a liquid material is deposited through a set of forming rolls or cold forming of centers from solid particulate. Drop roll forming is well known in the art and described in “Chocolate, Cocoa, and Confectionery Science and Technology,” 3rd ed., (1999) pp. 184-186, by B. W. Minifie. Cold forming is described in U.S. Pat. No. 6,270,826 for forming confectionery centers by taking solid particles of a fat based material such as chocolate flakes and compressing the particles in a set of forming rolls. The confectionery centers produced from either of these methods are typically further processed by applying a sugar shell coating over the outside of the centers.
When these sugar shelled confectionery products have a fat based center, they tend to develop quality problems when exposed to heat. This is evident in warm climates where shell cracking and fat bleeding are major consumer issues. The heat in the warm climate causes thermal expansion, which leads to cracks in the shell and ultimately enables fat to bleed through the shell.
One method that has been found to reduce thermal expansion issues is to aerate the fat based material that is used to form the fat based center. Compressed air is added into the fat based material when it is a liquid to create a homogenous dispersion of small void spaces. It is hypothesized that when thermal treatment is applied, e.g. higher temperatures, the presence of the hollow section in the formed confectionery center enables the fat based material to expand partially into the void space, thus reducing the expansion forces on the shell.
However, aeration methods have several disadvantages. When drop roll forming methods are used to form centers from liquid, the level of aeration in the formed confectionery center is very limited. Typically, the pressure exerted by the drop rolls squeezes some of the compressed air out of the fat based material as the fat based centers are formed. As this process occurs, air trapped in the liquid is squeezed out and released into the environment. Prior art aeration techniques with liquid chocolate have only managed to incorporate less than 4.65% by weight of the air into the fat based material. However, at these low levels of aeration the benefit is only apparent up to certain temperatures. A higher level of aeration is desirable to increase the benefits gained from the void spaces, further reducing and eliminating expansion and cracking defects. Aerating the fat based material when using drop rolls can also be costly, creating a continuous expense since compressed air must be constantly blended into the fat based material. Moreover, aeration techniques add to the complexity of the manufacturing process and often produce inconsistent results.
When using cold forming technology, it is not possible to use aeration to form a confectionery center with void spaces. As mentioned above, compressed air can be added to a liquid to create an aerated material. In cold forming technology, solid particles are compressed to form a shaped confectionery center. This would require having the liquid aerated confectionery material first be solidified then formed into small particulates before forming it into shaped centers. This process would destroy much of the voids created during aeration. Additionally, the cold forming process itself would exert a higher level of pressure on the confectionery material than a drop roll process compressing and releasing much of the trapped air.
A means of preventing or reducing product issues related to heat exposure would improve product quality and be more appealing to consumers. A means of creating confectionery centers produced by cold forming, which have the benefits of aeration is needed. Overall, a higher level of void spaces (aeration or density reduction) is desired for increased benefits in product quality of sugar shelled confectionery centers.